At one time the known scientist, popularizer of физико-математических sciences Yakov Перельман, created the new type of book of problems - evidential, teaching, merry. Years passed, and his heritage does not lose the actuality. It and not surprising, the tasks offered to in fact them develop the logical thinking, observation and good sense. And main - show, as far as there can accessible and interesting be a study of mathematics, physicists and to astronomy. This edition can become an original manual on an intellectual gymnastics for the most curious guys, in fact on the pages of book they will find the great number of ingenious puzzles, entertaining tasks, easy to understand explanations and colourful illustrations. Paradoxical questions, that физико-математические laws, and also geometrical riddles, arithmetic focuses, optical illusions and labyrinths, are the basis of logical capabilities, imagination, ability to see their curious essence in the ordinary phenomena, will help to develop.This book for all, who wants and able to study!For middle school age.